ULTIMATE LOW THRESHOLD AND LARGE SCALE INTEGRATION OF SEMICONDUCTOR MICRODISK LASERS

在这项研究中，我们研究了微盘半导体激光器的尺寸缩小、阈值降低、珀塞尔效应等自发辐射控制的实现以及它们的高集成度和光子分子的形成。首先，我们利用光泵浦技术实现了GaInAsP器件的室温连续工作。该装置的最小直径为1.7微米，与该装置的最小记录相同。此外，最低阈值低至19微米，这是GaInAsP激光器的最低记录。我们还集成了金属电极，观察到了电流注入激光。在本实验中，发现了聚酰亚胺包覆层中的非热效应，它稳定了激光波长。然后，我们提出了一种沿微盘边缘具有旋转对称光栅的微齿轮腔。我们从理论上发现，齿轮形状从根本上改善了空腔Q因子。实际上，我们成功地将阈值降低到了14微瓦。这些器件的自发辐射因子都在0.1以上，接近形成光子分子所需的大的Purcell因子6.7微米。该光子分子具有独特的模式分裂、抗交叉特性、微带形成和双稳特性，在未来的功能光子电路和光子存储中具有广阔的应用前景。

In this study, we investigated the size reduction, threshold reduction, and the realization of the spontaneous emission control such as Purcell effect in microdisk semiconductor lasers, and their high integration and the formation for photonic molecule. First, we achieved the room temperature continuous wave operation of GaInAsP device by photopumping. The smallest diameter of the device was 1.7 microns, which is the same as the smallest record of this device. In addition, the lowest threshold was as low as 19 microns, which is the lowest record for GaInAsP lasers. We also integrated the metal electrode and observed the current injection lasing. In this experiment, an athermal effect in the polyimide cladding layer was discovered, which stabilizes the lasing wavelength. Then, we proposed a microgear cavity having a rotationally symmetric grating along the periphery of the microdisk. We theoretically found that the gear shape essentially improves the cavity Q factor. Actually, we successfully reduced the threshold to 14 microwatts. The spontaneous emission factor of these devices were evaluated to be over 0.1, which is close to the large Purcell factor of 6.7 was 0.1 micros to form a photonic molecule. A unique mode splitting, anti-crossing characteristics, miniband formation and bistable characteristics were observed for the photonic molecule, which are promising for future functional photonic circuits and photonic memories.